Resilient bacterium from the Siberian permafrost could survive on the inhospitable surface of Mars

Researchers from the University of Florida and the Russian Academy of Sciences have conducted a groundbreaking study of strains of bacteria which are known to survive in the inhospitable conditions of eastern Siberia. They extracted a number of strains of bacteria from the banks of the Kolyma River at depths of 12 to 20 metres. Here the soil has an average temperature of minus 7C.

The international experts - Wayne Nicholson, Kirill Krivushin, David Gilichinsky and Andrew Schuerger - say the microbes had endured such conditions for between 6,000 and 8,000 years. In the laboratory, these cultures emulated a journey from the Siberian permafrost to Mars. 

They were subjected to a severe lack of oxygen, extreme cold temperatures, and very low pressure (about 150 times lower than the Earth's, about 7 millibars). More than 10,000 isolates were exposed to these Martian conditions. Only six survived.  

More than that - they thrived over a 30 day period. 

Further analysis showed they all come from  the same genus: an extremely hardy extremophile called Carnobacterium, which is common in exceptionally cold climates, for example Siberia, Alaska and Antarctica.

It is even used a food additive for vacuum or modified atmosphere-packaged ready-to-eat and processed meats. 

This raises the question of whether it could contaminate the Martian landscape by unwittingly finding its way onto a space probe bound for the planet. 

'The ability of terrestrial microorganisms to grow in the near-surface environment of Mars is of importance to the search for life and protection of that planet from forward contamination by human and robotic exploration,' said the research team. 

The study was published in the Proceedings of the National Academy of Sciences.